Venous Access Port Assembly with X-Ray Discernable Indicia

ABSTRACT

A venous access port assembly ( 10 ) having a housing base ( 22 ) with a discharge stem ( 16 ), a septum ( 14 ), a cap ( 20 ) and an interior reservoir ( 26 ). The port assembly ( 10 ) is provided with X-ray discernable indicia ( 60,62 ) to identify an attribute of the assembly ( 10 ) after its implantation and clearly appear on an X-ray of the patient in a manner informing the radiologist or technologist and the medical practitioner of that particular attribute. The indicia are cutouts ( 60,62 ) through a reservoir lining ( 50 ) of radiopaque material such as metal where the cutouts have narrow slot width are in the form of one or more sets of alphabetical letters such as “CT” in the lining&#39;s side wall ( 52 ) or bottom wall ( 54 ).

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit of U.S. Provisional PatentApplication Ser. No. 60/961,160 filed Jul. 19, 2007.

FIELD OF THE INVENTION

This relates to the field of medical devices and more particularly tovenous access ports for the infusion of fluids into the patient and/orwithdrawal of fluids from the patient.

BACKGROUND OF THE INVENTION

Venous access ports for the infusion and/or withdrawal of fluids from apatient are well-known, secured to the proximal end of an implantedcatheter. These ports are typically used for drug infusion or forwithdrawal of small amounts of blood, where large flows of fluid are notrequired. The ports are assemblies of a needle-impenetrable housing witha discharge port in fluid communication with the catheter and thereservoir within the port housing, and provide a subcutaneousself-sealing septum that defines an access site for multiple needlesticks through the covering skin tissue of the patient, through theseptum and into the reservoir, without the need to continuously searchfor new access sites. Examples of such ports are disclosed, for example,in U.S. Pat. Nos. 4,704,103; 4,762,517; 4,778,452; 5,185,003; 5,213,574;5,637,102; and 5,833,654. In U.S. Pat. No. 5,833,654 is set forth a dualchamber port assembly having a metal casing as a liner in one of thechambers of the port assembly.

It is desired to provide a venous access port assembly that provides fora radiologist, radiology technologist, nurse and ultimately a medicalpractitioner to be able to discern an important property of the portassembly after the port assembly has been implanted into a patient.

BRIEF SUMMARY OF THE INVENTION

The present invention is related to a venous access port having ahousing and a septum, providing an interior reservoir and a passagewayextending from the reservoir through a stem of a discharge port toestablish fluid communication with a proximal end of a catheter lumen towhich the port assembly is secured prior to placement of the assemblyinto a patient. The port may optionally have more than one reservoir andassociated septum. The invention is the incorporation of X-raydiscernable indicia onto a venous access port that is discernible underX-ray examination to provide information concerning the nature or keyattribute of the venous access port, so that the practitioner,subsequent to the date of implantation thereof, can determine thatnature or key attribute under X-ray examination. One such key attributein particular would be, for example, that where the venous access portis rated to be used for power injection, such as used for contrast fluidinjection during a contrast enhanced computed tomography, the letters“CT” (for “computed tomography) would be provided on the port assemblyin such a manner that they are radiographically visible. The attributein this example is the property of the port's being adapted to withstandhigh pressures that are used for injection of contrast fluid into apatient, and the letters “CT” would be understood in medical practice toindicate that the port is suitable for the high pressure injection ofcontrast fluid.

In the preferred embodiment, a reservoir lining of radiopaque materialsuch as titanium, includes cutouts such as of letters “CT” (althoughother indicia may be utilized) through the body of the lining, with thecutouts being radiographically visible. The lining for the reservoir iscontained within the port housing and includes an aperture through theside wall for fluid communication with a discharge stem of the portassembly, establishing fluid communication with a catheter sealingly andsecurely affixed to the discharge stem of the assembly. The reservoirlining of titanium provides protection against penetration by a needlewhen it is inserted through the septum of the port assembly forinjection of fluid into the chamber. The letters “CT” are readable fromexterior of the patient in an X-ray. The lining may have several suchsets of cutouts located at various locations about the lining's sidewall and/or in the bottom wall thereof. The cutouts preferably aresubstantially narrow for exposing therethrough only a minimum amount ofplastic of the surrounding housing.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated herein and constitutepart of this specification, illustrate the presently preferredembodiments of the invention, and, together with the general descriptiongiven above and the detailed description given below, serve to explainthe features of the invention. In the drawings:

FIGS. 1 and 2 are an isometric view and an exploded view, respectively,of the venous access port assembly containing the present invention;

FIG. 3 is an isometric view of a reservoir lining of the presentinvention defining X-ray discernable indicia;

FIG. 4 is an enlarged view of portion of the lining of FIG. 3illustrating the cutout indicia provided by the lining; and

FIGS. 5 and 6 are cross-section views of the port of FIGS. 1 and 2.

DETAILED DESCRIPTION OF THE INVENTION

Certain terminology is used herein for convenience only and is not to betaken as a limitation on the present invention. The terms “distal” and“proximal” refer, respectively, to directions closer to and away fromthe insertion tip of a catheter in an implantable catheter assembly. Theterminology includes the words specifically mentioned, derivativesthereof and words of similar import. The embodiments illustrated beloware not intended to be exhaustive or to limit the invention to theprecise form disclosed. These embodiments are chosen and described tobest explain the principle of the invention and its application andpractical use and to enable others skilled in the art to best utilizethe invention.

Venous access port assembly 10 of FIGS. 1, 2, 5 and 6 includes a housing12 and a septum 14, with a discharge stem 16 extending from a distal end18 of the port assembly 10 to be attached securely and sealingly to theproximal end of a catheter (not shown). Cap 20 of housing 12 secures tohousing base 22 to in turn secure septum 14 in position in the portassembly 10 in a manner that exposes the top surface of the septum forneedle insertion. A passageway 24 (see FIGS. 5 and 6) extends from aninterior reservoir 26 to the distal tip opening 28 of discharge stem 16.A recess 30 is seen to be provided along both sides of discharge stem16, facilitating insertion of the discharge stem 16 into the catheterlumen and providing a clearance for a locking sleeve or clamp (notshown) utilized to compress the catheter lumen wall against the exteriorsurface of the discharge port 16 for assured sealed connection of thecatheter with the port assembly 10.

With reference now to FIGS. 2 to 4, showing reservoir lining 50 of thepresent invention, lining 50 is cup-shaped and is inserted into well 32of housing base 22 beneath septum 14, and secured therewithin. Lining 50is made of needle-impenetrable material such as metal, which may betitanium or stainless steel, and its side wall 52 and bottom wall 54protects the side walls 34 and bottom wall 36 of housing base 22defining well 32, from being penetrated by a needle (not shown) insertedinto and through septum 14 for injection of fluids into reservoir 26 orwithdrawal of blood therefrom. An aperture 56 near or at the bottom ofside wall 52, in alignment with a corresponding aperture 38 of housingbase 22, establishes fluid communication with passageway 24 of dischargestem 16 for fluid to pass between the reservoir 26 and the catheter andthus the patient. Discharge stem 16 may be a metal component such astitanium or stainless steel which would extend through aperture 38 ofthe housing base 22, to preferably be welded to lining 50.

In accordance with the present invention, the X-ray discernable indiciaare cutouts 60 formed through the body of lining 50, shown as thealphabetical letters “CT”. The letters “CT” are visible when the X-rayof the patient is viewed, readable from outside the lining 50 and areeasily discerned by the radiologist or technologist. In lining 50,preferably a plurality of sets of cutout indicia 60,62 are providedequi-angularly spaced about the circumference of the side wall 52 andthrough bottom wall 54 to assure that the indicia appear in the X-rayirrespective of the angular location at which the X-ray is taken. Withparticular reference to FIG. 4, it is preferable that the width of eachcutout slot 58 of the indicia or letters be as narrow as possible butstill be discernable by X-ray; the narrowness of the slots 58 minimizesany possibility that a needle inserted through the septum couldpenetrate through a slot of a cutout by chance, thus harming the patientand resulting in injection of fluid directly into the tissue surroundingthe port. The width of each cutout slot 58 would thus preferably be lesswide than the diameter of a needle. The set of cutout indicia 62 throughthe bottom wall may be dimensionally larger as a set, but still withnarrow slot width. Centering of the cutout indicia 62 along the bottomwall 54 positions the indicia directly beneath the reservoir and septum,minimizes any obscuring thereof by the structure of the venous accessport assembly, and the indicia may also be easily discernable should theport assembly be at an angle from the horizontal plane of the X-ray.

It will be appreciated by those skilled in the art that changes could bemade to the embodiments described above without departing from the broadinventive concept thereof. It is understood, therefore, that thisinvention is not limited to the particular embodiments disclosed, but itis intended to cover modifications within the spirit and scope of thepresent invention as defined by the appended claims.

1. A venous access port assembly for implantation into a patient,comprising: a housing having a discharge port, a needle-penetrableseptum and a cap securable to the housing and retaining the septumsecurely in the assembly, the housing having a housing base defining abottom wall of at least one reservoir, with the housing base having anoutwardly facing bottom surface, and the housing base including areservoir lining of radiopaque material defining X-ray discernableindicia that indicate an attribute of the assembly when an X-ray of thepatient is taken so that the practitioner can be advised of theattribute of the assembly after implantation.
 2. The assembly of claim1, wherein the reservoir lining is of needle-impenetrable material. 3.The assembly of claim 2, wherein the reservoir lining is metal.
 4. Theassembly of claim 3, wherein the reservoir lining is titanium.
 5. Theassembly of claim 2, wherein the X-ray discernable indicia comprise atleast one set of cutouts through a wall of the reservoir lining.
 6. Theassembly of claim 5, wherein the X-ray discernable indicia arealphabetical letters.
 7. The assembly of claim 5, wherein the X-raydiscernable indicia comprise a plurality of sets of cutouts through aside wall of the reservoir lining.
 8. The assembly of claim 5, whereinthe X-ray discernable indicia comprise at least one set of cutoutsthrough a bottom wall of the reservoir lining.
 9. The assembly of claim5, wherein the X-ray discernable indicia comprise a plurality of sets ofcutouts through a side wall and a bottom wall of the reservoir lining.10. The assembly of claim 5, wherein the cutouts are formed as narrowslots having widths only sufficiently wide to be X-ray discernable.